Mitogen activated protein kinase phospahtase-1 (MKP-1) is a dual specificity phosphatase that has a central role regulating intracellular signal transduction. MKP-1 is a potential molecular target for several human diseases. No potent or selective small molecule inhibitors of this protein phosphatase are known. This proposal will provide sufficient reagents to permit a high throughput screening of 100,000 compounds. [unreadable] [unreadable]